<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8" />
		<title></title>
		<style>
			*{
				margin: 0;
				padding: 0;
				border: 0;
				list-style: none;
			}
			#div1{
				width: 200px;
				height: 200px;
				background-color: green;
				border: 10px solid #000;
				position: absolute;
				left: 50%;
				top: 50%;
				margin: -110px 0 0 -110px;
			}
		</style>
	</head>
	<body>
		<div id="div1"></div>
	</body>
</html>